Expansion
T7 to T11 intercostal, T12 subcostal, L1 iliohypogastric and ilioinguinal
Expansion
- T7 to T11 - continuations of the intercostal nerves, running in the plane between internal oblique and transversus abdominis
- T12 - the subcostal nerve
- L1 - the iliohypogastric and ilioinguinal nerves, from the lumbar plexus
Dermatome landmarks:
- T7 - the epigastrium, just below the xiphoid
- T10 - the umbilicus
- L1 - the groin and the root of the scrotum
The neurovascular plane between internal oblique and transversus is the target of the transversus abdominis plane (TAP) block.
Because the nerves run segmentally and mostly transversely, a transverse incision cuts across fewer of them than a long paramedian one, and midline incisions cross none at all.